Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_struct2single”.

  FT_STRUCT2SINGLE converts all double precision numeric data in a structure
  into single precision, which takes up half the amount of memory compared
  to double precision. It will also convert plain matrices and cell-arrays.
  Use as
    x = ft_struct2single(x)
  Starting from MATLAB 7.0, you can use single precision data in your
  computations, i.e. you do not have to convert back to double precision.
  MATLAB version 6.5 and older only support single precision for storing
  data in memory or on disk, but do not allow computations on single
  precision data. After reading a single precision structure from file, you
  can convert it back with FT_STRUCT2DOUBLE.